Add Watermark to PDF
Stamp a diagonal text watermark on every page of your PDF. Type any watermark text, adjust the opacity and font size, choose a colour, then download. All processing runs locally in your browser.
Drop a PDF here or click to browse
How it works
This tool uses pdf-lib, a pure JavaScript PDF library. It loads your PDF in memory, draws your watermark text diagonally across the centre of each page using the HelveticaBold font at the opacity and size you choose, and downloads the result. Entirely in your browser.
Processing runs in your browser
All processing happens inside your browser tab. pdf-lib applies the watermark entirely in memory, with no network requests.
Related operations
For tagging each page with a numeric label, try PDF page numbers. To bundle watermarked files into one PDF, use merge PDF. For shrinking the marked output, see compress PDF.
Frequently asked questions
- How do I add a watermark to a PDF?
- Drop your PDF into the tool, type your watermark text (e.g. CONFIDENTIAL or DRAFT), adjust the opacity and size sliders, choose a colour, then click 'Add watermark' and download.
- Can I customise the watermark text?
- Yes. Type any text you like, common choices are CONFIDENTIAL, DRAFT, SAMPLE, or your company name.
- Will the watermark appear on every page?
- Yes. The watermark is stamped diagonally across every page of the PDF.
- Can the watermark be removed after adding it?
- The watermark is drawn directly into the PDF page content. It cannot be removed by the recipient without PDF editing software.
- Is my file private?
- Yes. Your PDF is processed entirely in your browser using pdf-lib. Our servers are not involved at any point.